Funny idea! Do you think it's really necessary? I'm hoping that - just like X1 fic was still written and read after X2 and comics fic at various points in the comics canon is still written and read - X-Men fandom will remain flexible enough to accept stories that don't take X3 into consideration. I find that with a canon so very complex and often contradictory writers often just choose one piece of it to be their canon and readers seem willing to go along with that. But maybe that's more a subject for a separate meta post: how do you deal with contradictory canon? I've proposed it as a panel topic for Con.txt, using three different fandoms as examples: Star Wars, X-Men and Harry Potter.